Commuters attempting to get out of downtown Vancouver on Friday evening found themselves boxed in by a slow-moving river of bicycles. At around 8:00 p.m., Critical Mass cyclists stopped traffic on the Lions Gate Bridge.

Vancouver Police had hoped that a meeting with the organizers of the massive bike protest would help ease the rush hour traffic mayhem normally associated with the demonstration.

But those hopes were dashed after as many as 3,000 bikers took over downtown streets Friday evening as part of Critical Mass, a monthly bike ride that circles the downtown core, blocking traffic and frequently causing angry confrontations with motorists.

Deputy Chief Steve Sweeney met with organizers on Friday morning and said he hoped cyclists would cooperate to make the ride less disruptive on one of the busiest traffic days of the year.

"We explained to them how the city already had a number of closures and areas to avoid," he said.

"They share our concerns for the safety of everyone involved."

VPD bike and motorcycle officers were assigned to the ride "to ensure it moves as safely and quickly through the city as possible with the least disruptions," Sweeney said.

He hoped organizers would share their route with police so authorities could inform motorists  about which streets to avoid.

Commuter warning

On Thursday, the VPD made an unusual plea for motorists to avoid the downtown core during Friday's rush hour in case downtown traffic becomes paralyzed.

"Fights, assaults, road race incidents. No one wins when these violent incidents occur," Vancouver Police chief Jim Chu said.

Police don't plan on ticketing many of the riders, saying it could just increase hostility.

While Vancouver mayor Gregor Robertson is an avid cyclist, and has ridden in the rally in the past, he feels it may be getting out of control.

"I don't support it in its current form right now," Robertson said. "I want to see change. I want to see the ride be a celebration."

Critical Mass begins at the Vancouver Art Gallery at 6:00 p.m. Friday and typically lasts several hours.